<!doctype html>
<html style='font-size:22px !important'>
<head>
<meta charset='UTF-8'><meta name='viewport' content='width=device-width initial-scale=1'>
<title>day04</title><link href='https://fonts.loli.net/css?family=Open+Sans:400italic,700italic,700,400&subset=latin,latin-ext' rel='stylesheet' type='text/css' /><style type='text/css'>html {overflow-x: initial !important;}:root { --bg-color:#ffffff; --text-color:#333333; --select-text-bg-color:#B5D6FC; --select-text-font-color:auto; --monospace:"Lucida Console",Consolas,"Courier",monospace; }
html { font-size: 14px; background-color: var(--bg-color); color: var(--text-color); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; -webkit-font-smoothing: antialiased; }
body { margin: 0px; padding: 0px; height: auto; bottom: 0px; top: 0px; left: 0px; right: 0px; font-size: 1rem; line-height: 1.42857; overflow-x: hidden; background: inherit; tab-size: 4; }
iframe { margin: auto; }
a.url { word-break: break-all; }
a:active, a:hover { outline: 0px; }
.in-text-selection, ::selection { text-shadow: none; background: var(--select-text-bg-color); color: var(--select-text-font-color); }
#write { margin: 0px auto; height: auto; width: inherit; word-break: normal; overflow-wrap: break-word; position: relative; white-space: normal; overflow-x: visible; padding-top: 40px; }
#write.first-line-indent p { text-indent: 2em; }
#write.first-line-indent li p, #write.first-line-indent p * { text-indent: 0px; }
#write.first-line-indent li { margin-left: 2em; }
.for-image #write { padding-left: 8px; padding-right: 8px; }
body.typora-export { padding-left: 30px; padding-right: 30px; }
.typora-export .footnote-line, .typora-export li, .typora-export p { white-space: pre-wrap; }
@media screen and (max-width: 500px) {
  body.typora-export { padding-left: 0px; padding-right: 0px; }
  #write { padding-left: 20px; padding-right: 20px; }
  .CodeMirror-sizer { margin-left: 0px !important; }
  .CodeMirror-gutters { display: none !important; }
}
#write li > figure:last-child { margin-bottom: 0.5rem; }
#write ol, #write ul { position: relative; }
img { max-width: 100%; vertical-align: middle; }
button, input, select, textarea { color: inherit; font: inherit; }
input[type="checkbox"], input[type="radio"] { line-height: normal; padding: 0px; }
*, ::after, ::before { box-sizing: border-box; }
#write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write p, #write pre { width: inherit; }
#write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write p { position: relative; }
p { line-height: inherit; }
h1, h2, h3, h4, h5, h6 { break-after: avoid-page; break-inside: avoid; orphans: 2; }
p { orphans: 4; }
h1 { font-size: 2rem; }
h2 { font-size: 1.8rem; }
h3 { font-size: 1.6rem; }
h4 { font-size: 1.4rem; }
h5 { font-size: 1.2rem; }
h6 { font-size: 1rem; }
.md-math-block, .md-rawblock, h1, h2, h3, h4, h5, h6, p { margin-top: 1rem; margin-bottom: 1rem; }
.hidden { display: none; }
.md-blockmeta { color: rgb(204, 204, 204); font-weight: 700; font-style: italic; }
a { cursor: pointer; }
sup.md-footnote { padding: 2px 4px; background-color: rgba(238, 238, 238, 0.7); color: rgb(85, 85, 85); border-radius: 4px; cursor: pointer; }
sup.md-footnote a, sup.md-footnote a:hover { color: inherit; text-transform: inherit; text-decoration: inherit; }
#write input[type="checkbox"] { cursor: pointer; width: inherit; height: inherit; }
figure { overflow-x: auto; margin: 1.2em 0px; max-width: calc(100% + 16px); padding: 0px; }
figure > table { margin: 0px !important; }
tr { break-inside: avoid; break-after: auto; }
thead { display: table-header-group; }
table { border-collapse: collapse; border-spacing: 0px; width: 100%; overflow: auto; break-inside: auto; text-align: left; }
table.md-table td { min-width: 32px; }
.CodeMirror-gutters { border-right: 0px; background-color: inherit; }
.CodeMirror-linenumber { user-select: none; }
.CodeMirror { text-align: left; }
.CodeMirror-placeholder { opacity: 0.3; }
.CodeMirror pre { padding: 0px 4px; }
.CodeMirror-lines { padding: 0px; }
div.hr:focus { cursor: none; }
#write pre { white-space: pre-wrap; }
#write.fences-no-line-wrapping pre { white-space: pre; }
#write pre.ty-contain-cm { white-space: normal; }
.CodeMirror-gutters { margin-right: 4px; }
.md-fences { font-size: 0.9rem; display: block; break-inside: avoid; text-align: left; overflow: visible; white-space: pre; background: inherit; position: relative !important; }
.md-diagram-panel { width: 100%; margin-top: 10px; text-align: center; padding-top: 0px; padding-bottom: 8px; overflow-x: auto; }
#write .md-fences.mock-cm { white-space: pre-wrap; }
.md-fences.md-fences-with-lineno { padding-left: 0px; }
#write.fences-no-line-wrapping .md-fences.mock-cm { white-space: pre; overflow-x: auto; }
.md-fences.mock-cm.md-fences-with-lineno { padding-left: 8px; }
.CodeMirror-line, twitterwidget { break-inside: avoid; }
.footnotes { opacity: 0.8; font-size: 0.9rem; margin-top: 1em; margin-bottom: 1em; }
.footnotes + .footnotes { margin-top: 0px; }
.md-reset { margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: top; background: 0px 0px; text-decoration: none; text-shadow: none; float: none; position: static; width: auto; height: auto; white-space: nowrap; cursor: inherit; -webkit-tap-highlight-color: transparent; line-height: normal; font-weight: 400; text-align: left; box-sizing: content-box; direction: ltr; }
li div { padding-top: 0px; }
blockquote { margin: 1rem 0px; }
li .mathjax-block, li p { margin: 0.5rem 0px; }
li { margin: 0px; position: relative; }
blockquote > :last-child { margin-bottom: 0px; }
blockquote > :first-child, li > :first-child { margin-top: 0px; }
.footnotes-area { color: rgb(136, 136, 136); margin-top: 0.714rem; padding-bottom: 0.143rem; white-space: normal; }
#write .footnote-line { white-space: pre-wrap; }
@media print {
  body, html { border: 1px solid transparent; height: 99%; break-after: avoid; break-before: avoid; }
  #write { margin-top: 0px; padding-top: 0px; border-color: transparent !important; }
  .typora-export * { -webkit-print-color-adjust: exact; }
  html.blink-to-pdf { font-size: 13px; }
  .typora-export #write { padding-left: 32px; padding-right: 32px; padding-bottom: 0px; break-after: avoid; }
  .typora-export #write::after { height: 0px; }
}
.footnote-line { margin-top: 0.714em; font-size: 0.7em; }
a img, img a { cursor: pointer; }
pre.md-meta-block { font-size: 0.8rem; min-height: 0.8rem; white-space: pre-wrap; background: rgb(204, 204, 204); display: block; overflow-x: hidden; }
p > .md-image:only-child:not(.md-img-error) img, p > img:only-child { display: block; margin: auto; }
p > .md-image:only-child { display: inline-block; width: 100%; }
#write .MathJax_Display { margin: 0.8em 0px 0px; }
.md-math-block { width: 100%; }
.md-math-block:not(:empty)::after { display: none; }
[contenteditable="true"]:active, [contenteditable="true"]:focus { outline: 0px; box-shadow: none; }
.md-task-list-item { position: relative; list-style-type: none; }
.task-list-item.md-task-list-item { padding-left: 0px; }
.md-task-list-item > input { position: absolute; top: 0px; left: 0px; margin-left: -1.2em; margin-top: calc(1em - 10px); border: none; }
.math { font-size: 1rem; }
.md-toc { min-height: 3.58rem; position: relative; font-size: 0.9rem; border-radius: 10px; }
.md-toc-content { position: relative; margin-left: 0px; }
.md-toc-content::after, .md-toc::after { display: none; }
.md-toc-item { display: block; color: rgb(65, 131, 196); }
.md-toc-item a { text-decoration: none; }
.md-toc-inner:hover { text-decoration: underline; }
.md-toc-inner { display: inline-block; cursor: pointer; }
.md-toc-h1 .md-toc-inner { margin-left: 0px; font-weight: 700; }
.md-toc-h2 .md-toc-inner { margin-left: 2em; }
.md-toc-h3 .md-toc-inner { margin-left: 4em; }
.md-toc-h4 .md-toc-inner { margin-left: 6em; }
.md-toc-h5 .md-toc-inner { margin-left: 8em; }
.md-toc-h6 .md-toc-inner { margin-left: 10em; }
@media screen and (max-width: 48em) {
  .md-toc-h3 .md-toc-inner { margin-left: 3.5em; }
  .md-toc-h4 .md-toc-inner { margin-left: 5em; }
  .md-toc-h5 .md-toc-inner { margin-left: 6.5em; }
  .md-toc-h6 .md-toc-inner { margin-left: 8em; }
}
a.md-toc-inner { font-size: inherit; font-style: inherit; font-weight: inherit; line-height: inherit; }
.footnote-line a:not(.reversefootnote) { color: inherit; }
.md-attr { display: none; }
.md-fn-count::after { content: "."; }
code, pre, samp, tt { font-family: var(--monospace); }
kbd { margin: 0px 0.1em; padding: 0.1em 0.6em; font-size: 0.8em; color: rgb(36, 39, 41); background: rgb(255, 255, 255); border: 1px solid rgb(173, 179, 185); border-radius: 3px; box-shadow: rgba(12, 13, 14, 0.2) 0px 1px 0px, rgb(255, 255, 255) 0px 0px 0px 2px inset; white-space: nowrap; vertical-align: middle; }
.md-comment { color: rgb(162, 127, 3); opacity: 0.8; font-family: var(--monospace); }
code { text-align: left; vertical-align: initial; }
a.md-print-anchor { white-space: pre !important; border-width: initial !important; border-style: none !important; border-color: initial !important; display: inline-block !important; position: absolute !important; width: 1px !important; right: 0px !important; outline: 0px !important; background: 0px 0px !important; text-decoration: initial !important; text-shadow: initial !important; }
.md-inline-math .MathJax_SVG .noError { display: none !important; }
.html-for-mac .inline-math-svg .MathJax_SVG { vertical-align: 0.2px; }
.md-math-block .MathJax_SVG_Display { text-align: center; margin: 0px; position: relative; text-indent: 0px; max-width: none; max-height: none; min-height: 0px; min-width: 100%; width: auto; overflow-y: hidden; display: block !important; }
.MathJax_SVG_Display, .md-inline-math .MathJax_SVG_Display { width: auto; margin: inherit; display: inline-block !important; }
.MathJax_SVG .MJX-monospace { font-family: var(--monospace); }
.MathJax_SVG .MJX-sans-serif { font-family: sans-serif; }
.MathJax_SVG { display: inline; font-style: normal; font-weight: 400; line-height: normal; zoom: 90%; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; }
.MathJax_SVG * { transition: none 0s ease 0s; }
.MathJax_SVG_Display svg { vertical-align: middle !important; margin-bottom: 0px !important; margin-top: 0px !important; }
.os-windows.monocolor-emoji .md-emoji { font-family: "Segoe UI Symbol", sans-serif; }
.md-diagram-panel > svg { max-width: 100%; }
[lang="mermaid"] svg, [lang="flow"] svg { max-width: 100%; height: auto; }
[lang="mermaid"] .node text { font-size: 1rem; }
table tr th { border-bottom: 0px; }
video { max-width: 100%; display: block; margin: 0px auto; }
iframe { max-width: 100%; width: 100%; border: none; }
.highlight td, .highlight tr { border: 0px; }
svg[id^="mermaidChart"] { line-height: 1em; }
mark { background: rgb(255, 255, 0); color: rgb(0, 0, 0); }
.md-html-inline .md-plain, .md-html-inline strong, mark .md-inline-math, mark strong { color: inherit; }
mark .md-meta { color: rgb(0, 0, 0); opacity: 0.3 !important; }


:root {
    --side-bar-bg-color: #fafafa;
    --control-text-color: #777;
}

@include-when-export url(https://fonts.loli.net/css?family=Open+Sans:400italic,700italic,700,400&subset=latin,latin-ext);

html {
    font-size: 16px;
}

body {
    font-family: "Open Sans","Clear Sans","Helvetica Neue",Helvetica,Arial,sans-serif;
    color: rgb(51, 51, 51);
    line-height: 1.6;
}

#write {
    max-width: 860px;
  	margin: 0 auto;
  	padding: 30px;
    padding-bottom: 100px;
}
#write > ul:first-child,
#write > ol:first-child{
    margin-top: 30px;
}

a {
    color: #4183C4;
}
h1,
h2,
h3,
h4,
h5,
h6 {
    position: relative;
    margin-top: 1rem;
    margin-bottom: 1rem;
    font-weight: bold;
    line-height: 1.4;
    cursor: text;
}
h1:hover a.anchor,
h2:hover a.anchor,
h3:hover a.anchor,
h4:hover a.anchor,
h5:hover a.anchor,
h6:hover a.anchor {
    text-decoration: none;
}
h1 tt,
h1 code {
    font-size: inherit;
}
h2 tt,
h2 code {
    font-size: inherit;
}
h3 tt,
h3 code {
    font-size: inherit;
}
h4 tt,
h4 code {
    font-size: inherit;
}
h5 tt,
h5 code {
    font-size: inherit;
}
h6 tt,
h6 code {
    font-size: inherit;
}
h1 {
    padding-bottom: .3em;
    font-size: 2.25em;
    line-height: 1.2;
    border-bottom: 1px solid #eee;
}
h2 {
   padding-bottom: .3em;
    font-size: 1.75em;
    line-height: 1.225;
    border-bottom: 1px solid #eee;
}
h3 {
    font-size: 1.5em;
    line-height: 1.43;
}
h4 {
    font-size: 1.25em;
}
h5 {
    font-size: 1em;
}
h6 {
   font-size: 1em;
    color: #777;
}
p,
blockquote,
ul,
ol,
dl,
table{
    margin: 0.8em 0;
}
li>ol,
li>ul {
    margin: 0 0;
}
hr {
    height: 2px;
    padding: 0;
    margin: 16px 0;
    background-color: #e7e7e7;
    border: 0 none;
    overflow: hidden;
    box-sizing: content-box;
}

li p.first {
    display: inline-block;
}
ul,
ol {
    padding-left: 30px;
}
ul:first-child,
ol:first-child {
    margin-top: 0;
}
ul:last-child,
ol:last-child {
    margin-bottom: 0;
}
blockquote {
    border-left: 4px solid #dfe2e5;
    padding: 0 15px;
    color: #777777;
}
blockquote blockquote {
    padding-right: 0;
}
table {
    padding: 0;
    word-break: initial;
}
table tr {
    border-top: 1px solid #dfe2e5;
    margin: 0;
    padding: 0;
}
table tr:nth-child(2n),
thead {
    background-color: #f8f8f8;
}
table tr th {
    font-weight: bold;
    border: 1px solid #dfe2e5;
    border-bottom: 0;
    margin: 0;
    padding: 6px 13px;
}
table tr td {
    border: 1px solid #dfe2e5;
    margin: 0;
    padding: 6px 13px;
}
table tr th:first-child,
table tr td:first-child {
    margin-top: 0;
}
table tr th:last-child,
table tr td:last-child {
    margin-bottom: 0;
}

.CodeMirror-lines {
    padding-left: 4px;
}

.code-tooltip {
    box-shadow: 0 1px 1px 0 rgba(0,28,36,.3);
    border-top: 1px solid #eef2f2;
}

.md-fences,
code,
tt {
    border: 1px solid #e7eaed;
    background-color: #f8f8f8;
    border-radius: 3px;
    padding: 0;
    padding: 2px 4px 0px 4px;
    font-size: 0.9em;
}

code {
    background-color: #f3f4f4;
    padding: 0 2px 0 2px;
}

.md-fences {
    margin-bottom: 15px;
    margin-top: 15px;
    padding-top: 8px;
    padding-bottom: 6px;
}


.md-task-list-item > input {
  margin-left: -1.3em;
}

@media print {
    html {
        font-size: 13px;
    }
    table,
    pre {
        page-break-inside: avoid;
    }
    pre {
        word-wrap: break-word;
    }
}

.md-fences {
	background-color: #f8f8f8;
}
#write pre.md-meta-block {
	padding: 1rem;
    font-size: 85%;
    line-height: 1.45;
    background-color: #f7f7f7;
    border: 0;
    border-radius: 3px;
    color: #777777;
    margin-top: 0 !important;
}

.mathjax-block>.code-tooltip {
	bottom: .375rem;
}

.md-mathjax-midline {
    background: #fafafa;
}

#write>h3.md-focus:before{
	left: -1.5625rem;
	top: .375rem;
}
#write>h4.md-focus:before{
	left: -1.5625rem;
	top: .285714286rem;
}
#write>h5.md-focus:before{
	left: -1.5625rem;
	top: .285714286rem;
}
#write>h6.md-focus:before{
	left: -1.5625rem;
	top: .285714286rem;
}
.md-image>.md-meta {
    /*border: 1px solid #ddd;*/
    border-radius: 3px;
    padding: 2px 0px 0px 4px;
    font-size: 0.9em;
    color: inherit;
}

.md-tag {
    color: #a7a7a7;
    opacity: 1;
}

.md-toc { 
    margin-top:20px;
    padding-bottom:20px;
}

.sidebar-tabs {
    border-bottom: none;
}

#typora-quick-open {
    border: 1px solid #ddd;
    background-color: #f8f8f8;
}

#typora-quick-open-item {
    background-color: #FAFAFA;
    border-color: #FEFEFE #e5e5e5 #e5e5e5 #eee;
    border-style: solid;
    border-width: 1px;
}

/** focus mode */
.on-focus-mode blockquote {
    border-left-color: rgba(85, 85, 85, 0.12);
}

header, .context-menu, .megamenu-content, footer{
    font-family: "Segoe UI", "Arial", sans-serif;
}

.file-node-content:hover .file-node-icon,
.file-node-content:hover .file-node-open-state{
    visibility: visible;
}

.mac-seamless-mode #typora-sidebar {
    background-color: #fafafa;
    background-color: var(--side-bar-bg-color);
}

.md-lang {
    color: #b4654d;
}

.html-for-mac .context-menu {
    --item-hover-bg-color: #E6F0FE;
}

#md-notification .btn {
    border: 0;
}

.dropdown-menu .divider {
    border-color: #e5e5e5;
}

.ty-preferences .window-content {
    background-color: #fafafa;
}

.ty-preferences .nav-group-item.active {
    color: white;
    background: #999;
}


</style>
</head>
<body class='typora-export os-windows' >
<div  id='write'  class = 'is-node'><p><span>三大框架，讲8天，后面第三个月</span></p><p><span>1，复习</span></p><p><img src="day04.assets/image-20210118091027639.png" referrerpolicy="no-referrer" alt="image-20210118091027639"></p><p><span>2，Spring</span></p><p><span>2.1解决什么问题</span></p><p><span>  业务层：对数据处理。需要对象，以前是自己new对象，管理对象，可以把对象放在list或map中</span></p><p><span>2.2 是什么</span></p><p><span>	</span><span>是业务层框架，主要有两个功能</span></p><p><span>   2.2.1是ioc容器，ioc容器提供了一个hashMap</span></p><p><span>	</span><span>2.2.2 aop功能，动态代理</span></p><p><span>2.3 如何用</span></p><p><span>	</span><span>2.3.1 通过xml配置方式使用</span></p><p><span>	</span><span>2.3.2 创建springboot项目，内置了spring</span></p><p><span>3,spring ioc容器案例</span></p><p><span> 3.1 拷贝webdemo,直接解压，把文件夹改名成spring01_ioc,修改pom.xml中的antifactid和name,eclipse --&gt;import--&gt;maven--&gt;existing maven projects</span></p><p><span>3.2 在主包下面创建controller,创建UserController</span></p><p><span>@autowired  spring框架会从ioc容器中取一个对象赋值给userService</span></p><p><span>UserService userService</span></p><p><span>3.3创建业务层service</span></p><p><span>	</span><span>interface UserService{register}</span></p><p><span>	</span></p><p><span>@Service 与controller功能类似，由spring创建UserServiceImpl类的对象</span></p><p><span>对象放在spring 框架中的ioc容器(hashMap)</span></p><p><span>class UserServiceImpl implements UserService</span></p><p><span>    class UserServiceImpl2</span></p><p><span>以前创建对象 UserServiceImpl userServiceImpl=new UserServiceImpl ()</span></p><p><span>创建对象时  UserService userService=new  UserServiceImpl2();</span></p><p>&nbsp;</p><p><span>4，生命周期</span></p><p><span>对象什么时候创建，什么时候被回收</span></p><p><span>controller默认是系统启动时创建，系统关闭时回收</span></p><p><span>@scope(&quot;singleton&quot;)单例，只创建一个对象</span></p><p><span>@scope(&quot;protoType&quot;) 原型，每次从容器中取对象时，创建新的</span></p><p><img src="day04.assets/image-20210118104358018.png" referrerpolicy="no-referrer" alt="image-20210118104358018"></p><p><a href='https://gitee.com/jiujun_1/code2011' target='_blank' class='url'>https://gitee.com/jiujun_1/code2011</a></p><p><span>5，业务层有多个实现类</span></p><p><span>spring框架到ioc容器中找到所有的对象判断这个对象的类型如果是UserService,赋值</span></p><p><span>@autowired</span></p><p><span>UserService userSerivce</span></p><p>&nbsp;</p><p><span>interface UserService</span></p><p><span>class UserServiceImpl</span></p><p><span>@service</span></p><p><span> class UserServiceImpl2 implements UserService</span></p><p>&nbsp;</p><p><span>No qualifying bean of type &#39;com.tedu.webDemo.service.UserService&#39; available: expected single matching bean but found 2: userServiceImpl,userServiceImpl2</span></p><p><span>6，小结</span></p><p><img src="day04.assets/image-20210118120010466.png" referrerpolicy="no-referrer" alt="image-20210118120010466"></p><p><img src="day04.assets/image-20210118120439301.png" referrerpolicy="no-referrer" alt="image-20210118120439301"></p><p><span>工作中</span></p><p><img src="day04.assets/image-20210118120535884.png" referrerpolicy="no-referrer" alt="image-20210118120535884"></p><p><span>7,mybatis框架</span></p><p><span>7.1解决什么问题</span></p><p><span> 以前是用jdbc操作数据库，需要我们创建连接，拼出sql,得到结果集resultSet,遍历resultSet,取数据，创建对象，给对象属性赋值，放到list中</span></p><p><span>7.2 是什么</span></p><p><span>	</span><span>是一个数据库框架，</span></p><p><span>   以前用的是hibernate</span></p><p><span>7.3如何用</span></p><p><span>		</span><span>1,创建springboot项目，添加mybatis,mysql依赖</span></p><p><span>		</span><span>2，使用代码生成sql,pojo类</span></p><p><span>		</span><span>3，创建controller,service调用数据库</span></p><p><img src="day04.assets/image-20210118140958738.png" referrerpolicy="no-referrer" alt="image-20210118140958738"></p><p><span>8，创建数据库</span></p><p><span>	</span><span>1，找到课前资料/code/mall.sql</span></p><p><span>	</span><span>2,打开sqlyog,打开执行sql语句的窗口</span></p><p><span>	</span><span>3，把sql拷贝到sqlyog中，执行</span></p><p><span>	</span><span>4，选中服务器，右键 refresh,看到一个库mall,里面有5张表admin,category,item,jt_order,user。</span></p><p>&nbsp;</p><p><span>9，生成sql,pojo类</span></p><p><span>以前使用mybatis是用xml配置</span></p><p><span>现在使用mybatis是用springboot yml配置</span></p><p><img src="day04.assets/image-20210118142547839.png" referrerpolicy="no-referrer" alt="image-20210118142547839"></p><p><span>	</span><span>1，拷贝课前资料code/generator原始.rar到工作区，解压</span></p><p><span>	</span><span>2，eclipse--&gt;import --&gt;maven--&gt;existing maven projects</span></p><p><span>	</span></p><p><span>10，mybatis项目</span></p><p><span>		</span><span>1，用start.spring.io网站生成</span></p><p><span>        2，项目没有配置url，就启动报错</span></p><p><span>Failed to configure a DataSource: &#39;url&#39; attribute is not specified and no embedded datasource could be configured.</span></p><p><span>       3，拷贝生成的mapper和pojo两个包</span></p><p><span>		</span><span>4，拷贝application.properties,改名成application.yml，从讲义拷贝配置</span></p><p><span>11，mybatis的使用</span></p><p><span>     </span><span>	</span><span>1，拷贝code/dbDemo到工作区中，把文件夹改名成mybatis02,修改pom.xml中的artifaceId和name, import ,启动，报错。</span></p><p><span>		</span><span>2，拷贝生成的代码，拷贝com</span></p><p><span>       3, com.tedu.project_jt.mapper</span></p><p><span>       </span><span>										</span><span>.pojo</span></p><p><span>												</span><span>.controller</span></p><p><span>												</span><span>DBDemoApplication</span></p><p><span>		</span><span>4,拷贝application.properties改名成application.yml,拷贝配置，修改数据库信息，修改mapplocation和log的包名</span></p><p><span> </span><span>		</span><span> 5，入口类上@mapperScan(&quot;com.tedu.project_jt.mapper&quot;)</span></p><p><span>		</span><span> 6,创建controller</span></p><p><span>		</span><span>7,装jsonView</span></p><p>&nbsp;</p><p><span>如果在入口类中不配置mapperScan</span></p><p><span>Field userMapper in com.tedu.project_jt.controller.UserController required a bean of type &#39;com.tedu.project_jt.mapper.UserMapper&#39; that could not be found.</span></p><p><span>The injection point has the following annotations:</span>
<span>	</span><span>- @org.springframework.beans.factory.annotation.Autowired(required=true)</span></p><p><span>Action:</span></p><p><span>Consider defining a bean of type &#39;com.tedu.project_jt.mapper.UserMapper&#39; in your configuration.</span></p><p><span>12 安装jsonview</span></p><p><span>课前资料 \sofware\jsonView</span></p><p><span>13 总结</span></p><p><span>13.1 spring ioc容器</span></p><p><span>UserController需要UserServiceImpl的对象,自己new</span></p><p><span>UserController被UserServiceImpl控制。</span></p><p><span>@autowired 容器给我一个对象</span></p><p><span>UserService userServiceImpl1</span></p><p>&nbsp;</p><p><span>@service</span></p><p><span>class UserServiceImpl1</span></p><p><span>class UserServiceimpl2</span></p><p>&nbsp;</p><p>&nbsp;</p><p><span>先遍历hashmap,取出所有对象，看对象的类型是否是UserService,</span></p><p><span>根据类型找对象可能会失败，一个是hashMap中没有对象，另一个是有多个对象。</span></p><p><span>hashMap.get(userServiceImpl1),根据对象名称去找一个对象</span></p><p>&nbsp;</p><p><span>mybatis解决什么问题</span></p><p><span>对jdbc封装</span></p><p>&nbsp;</p><p><span>使用步骤</span></p><p><span>		</span><span>1，创建一个springboot项目，添加mysql,mybatis,web依赖</span></p><p><span>		</span><span>2，用代码生成UserMapper.xml,UserMapper.java,User</span></p><p><span>		</span><span>3, 在application.yml配置数据库信息，mapperLocation,log</span></p><p><span>		</span><span>4,在入口类*Applicaiton添加@mapperScan(&quot;&quot;)，mybatis框架会为mapper包上的接口创建代理类$Proxy51,为$Proxy51类创建对象，放在spring ioc容器中</span></p><p><span>		</span><span>5，在controller 中@autowired取到userMapper对象，调用方法</span></p><p>&nbsp;</p><p><span>软件是对数据的处理，把处理的结果显示在屏幕上。</span></p><p><span>中小型项目用vue+ssm</span></p><p><span>大型项目用 vue +ssm+redis+微服务+docker</span></p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p></div>
</body>
</html>